AUGUSTA, Maine — Republican Shawn Moody and Democrat Janet Mills are in a dead heat in the 2018 race to replace term-limited Maine Gov. Paul LePage, according to a poll from a Massachusetts university signaling a muddled state and no midterm slam dunk for Democrats.

The poll of 500likely voters from the Suffolk University Political Research Center finds that Moody, a Gorham businessman, and Mills, the Maine attorney general, are tracking toward a close November election that could be influenced by the two trailing independents in the race.

The Suffolk poll also found that President Donald Trump has a steady, yet underwater approval rating in Maine, U.S. Sen. Angus King will be heavily favored to keep his seat in November and signs of worry for supporters of a referendum to create a universal home care program. Races in Maine’s two U.S. House districts weren’t polled.

Little separates Moody and Mills but the independents and stark demographic differences in their supporters. The poll found Moody and Mills in a dead statistical heat in the race at 39 percent each, with an error margin of plus or minus 4.4 percentage points. Nearly 16 percent of voters were undecided.

The two left-leaning independents in the race — State Treasurer Terry Hayes and consultant Alan Caron of Freeport — have failed to gain early traction, with 4 percent and 2.6 percent, respectively. But that may change, and if the Moody-Mills race remains close, they could be major factors in the outcome.

“This margin is so razor-thin that anything can impact it,” said David Paleologos, the director of the Suffolk center that conducted the poll.

Mills led among women by 48 percent to 29 percent over Moody. Moody led by 50 percent to 29 percent over Mills with men. Gun owners broke for Moody with 50 percent to 26 percent over Mills. He bests her among voters between ages 18 to 34 and over age 65 and in northern and midcoast regions. She leads him among middle-aged voters and in southern Maine.

Gubernatorial voters are concerned mainly about two issues — health care and the economy, with 28.2 percent of Mainers surveyed picking the former as the most important issue to them and 25.6 percent picking the latter. Taxes and education were next at 11.6 percent and 11.2 percent, respectively.

Democrats are hoping for a national “blue wave” in an election midway through Trump’s first term, but his approval rating is steady here. The Republican president lost Maine overall to Democrat Hillary Clinton in 2016, but Trump won the northern 2nd Congressional District in a historic split. Since then, his approval rating has been steadily underwater here.

The Suffolk poll was another sign of that, pegging Trump’s approval rating at 41 percent to 54 percent who found him unfavorable. Morning Consult found 48 percent approval in Maine for Trump in June, but this result more or less matches several past polls on that issue.

Nationally, Democrats are counting on a midterm backlash to Trump in their bids to retake both chambers of Congress as part of a “blue wave.” There could be a close race in Maine’s 2nd District between U.S. Rep. Bruce Poliquin, a Republican, Assistant Maine House Majority Leader Jared Golden, D-Lewiston, and two independents.

There were some good signs for Democrats in the poll, with 46 percent saying they want their November vote to change the way Trump is leading the country. Another 29.6 percent said they want to support it, and 20.6 percent said their vote doesn’t have much to do with Trump. Just 4 percent said they regretted their presidential vote in 2016.

But predictably, Trump’s support varies widely by region here. In northern Maine, 49 percent of people in the survey approved of him, compared with 33 percent in eastern Maine. So, the president could affect other candidates unevenly in Maine for better or worse.

King is leading widely and among all major demographics in his re-election race. The former two-term governor from Brunswick and independent who caucuses with Democrats had 51.6 percent of votes in the poll, well ahead of state Sen. Eric Brakey, R-Auburn, at 25 percent and Democrat Zak Ringelstein of Falmouth at 8.8 percent, with 14.6 percent of voters undecided.

King’s challengers look to be running into a buzzsaw in the ranked-choice race. The poll found that King had a 63 percent approval rating — more than anyone else on the ballot here in 2018. He also led among all major demographics, including gun owners.

The home care referendum had majority support, but it could be soft. The referendum that would place a total of 3.8 percent in payroll taxes on income above $127,200 to fund a universal home care program for Mainers 65 and older led with 51.4 percent to 34.4 percent against it with another 14.2 percent undecided.